1. Field of the Invention
The present invention relates to a sound absorbing assembly for a vacuum cleaner, and more particularly to a sound absorbing assembly for a vacuum cleaner which has a simple internal structure and a low manufacturing cost and is convenient to assemble.
2. Description of the Prior Art
A variety of vacuum cleaners for easily removing dust or other foreign substances piled up on furniture, a floor, or a carpet in a room have been proposed hitherto. Generally, vacuum cleaners can be classified into canister-type vacuum cleaners and upright-type vacuum cleaners.
A canister-type vacuum cleaner includes a body mounted on wheels and a hose assembly for sucking dust or other foreign substances into the body. A suction generating means such as a suction fan, a motor for driving the suction generating means, and a disposable dust container for filtering dust or other foreign substances from air sucked by the vacuum cleaner, are positioned in the body. A main brush and a suction nozzle are provided at a free end of the hose assembly.
An upright-type vacuum cleaner has a constitution which is similar to that of the canister-type vacuum cleaner. However, the upright-type vacuum cleaner differs in that it vacuums a surface directly beneath its body, so a hose assembly is not required.
These days, the canister-type vacuum cleaner is more frequently used in the home than the upright-type vacuum.
FIG. 5 illustrates a canister-type vacuum cleaner 100. Vacuum cleaner 100 includes a floor cleaning unit 110, a canister unit 120, and a hose assembly 130 extending between floor cleaning unit 110 and canister unit 120.
Floor cleaning unit 110 includes a main brush (not shown) or a suction nozzle (not shown), and the like. Floor cleaning unit 110 is detachably connected to hose assembly 130.
Canister unit 120 mainly includes a hood 122, a cover 124 and a body 126. Hood 122 encloses a dust collecting compartment 140 (refer to FIG. 6) and is pivotally installed onto body 126 so that dust collecting compartment 140 can be opened and closed. Hood 122 is provided with a suction port 127 formed through hood 122 for receiving hose assembly 130. Hood 122 also is provided with a transparent window 128 for notifying the user of the dust collecting state. Cover 124 encloses a motor compartment 150 (referred to FIG. 6) where an electric motor and a suction fan driven by the electric motor are positioned.
Hose assembly 130 comprises a rigid wand 132 and a flexible hose 134. Rigid wand 132 is rotatably connected to flexible hose 134 by a handle assembly 131. Hose assembly 130 is pneumatically connected to a dust collecting compartment 140 of canister unit 120 by a suction hose connector 136.
FIG. 6 schematically illustrates an internal structure of canister unit 120. In body 126 of canister unit 120, dust collecting compartment 140 and motor compartment 150 are formed. That is, a grill portion 160 divides an interior of canister unit 120 into dust collecting compartment 140 and motor compartment 150. A suction opening 162 is formed through a central portion of grill portion 160. Suction opening 162 pneumatically connects dust collecting compartment 140 with motor compartment 150.
In dust collecting compartment 140, a dust container 142 is accommodated. Dust container 142 includes a flat collar 144 made of strawboard and a receptacle portion 146 made of porous paper. Collar 144 is combined with receptacle portion 146 by glue. Dust container 142 is mounted on dust container mounting portion 148 by means of collar 144. At dust container mounting portion 148, dust container 142 is pneumatically connected to hose assembly 130 by a suction hose connector 136 (refer to FIG. 5).
In motor compartment 150, a sound absorbing assembly 170 and an electric cord reel 190 for applying an electric power from an outer electric source to sound absorbing assembly 170 are positioned. Sound absorbing assembly 170 is disposed between grill portion 160 and a fixing rib 164. Fixing rib 164 is formed across motor compartment 150 at a rear portion of motor compartment 150. A plurality of anti-vibration rubber rings 166 are disposed between grill portion 160 and a front end of sound absorbing assembly 170. Anti-vibration rubber rings 166 alleviate a vibration of sound absorbing assembly 170 during the operation of vacuum cleaner 100. Further, anti-vibration rubber rings 166 prevent air, which is introduced from dust collecting compartment 140 through suction opening 162 to motor compartment 150, from leaking around sound absorbing assembly 170. An exhaust port 168 is formed at a rear side of fixing rib 164. Exhaust port 168 is a passageway for air to flow out. That is, exhaust port 168 exhausts the air which is exhausted from sound absorbing assembly 170, to the outside of vacuum cleaner 100.
FIGS. 7A to 7C illustrate sound absorbing assembly 170 of the conventional vacuum cleaner 100 in detail. Sound absorbing assembly 170 includes a front casing 172, a front cap 174, a motor assembly 176, an air guide 178, a rear casing 180 and a rear cap 182. Front casing 172 includes a first suction port 171 which is formed in a central portion of front casing 172. First suction port 171 is a passageway for air to flow into sound absorbing assembly 170. Front casing 172 includes a plurality of first flanges 173 protruding radially outward at an opening end 172a of front casing 172. First locking holes 175 are formed in first flanges 173 respectively.
Front cap 174 is disposed between front casing 172 and motor assembly 176. Front cap 174 alleviates a vibration which is generated during the operation of a motor (not shown) installed in motor assembly 176. Front cap 174 includes a second suction port 177 which is formed in a central portion of the front cap 174. Second suction port 177 stands in a row with first suction port 171, which is formed in front casing 172. Second suction port 177 is a passageway for air to flow in.
Motor assembly 176 includes a motor, a suction fan (not shown) which is driven by the motor, and a motor casing for enclosing the motor and the suction fan. The motor is integrally formed with the suction fan. When an electric power is applied from an outer electrical source to motor assembly 176, the motor is operated and drives the suction fan. Then, the suction fan is rotated and generates a vacuum suction force. A third suction port 179 is formed in a central portion of a front end 175a of motor casing 175. Third suction port 179 is a passageway for air to flow into motor assembly 176. A plurality of first exhaust ports 176a are formed at a rear half portion 175b of motor casing 175.
Air guide 178 encloses rear half portion 175b of motor casing 175 and guides air which is exhausted from motor assembly 176 through first exhaust ports 176a. A first through hole 178b (as indicated by dotted line)is formed in a central portion of a rear end 178a of air guide 178. First through hole 178b receives a rear end 176b of motor assembly 176 and rear cap 182 during the assembling of sound absorbing assembly 170.
Rear casing 180 includes a second through hole 181 (as indicated by dotted line) which is formed through a central portion of a closing end 180a of rear casing 180. Second through hole 181 receives rear cap 182 during the assembling of sound absorbing assembly 170. A plurality of second exhaust ports 181a (as indicated by dotted line) are formed around second through hole 181. Second exhaust ports 181 are passageways for air to flow out. That is, second exhaust ports 181 allows air exhausted from motor assembly 176 into sound absorbing assembly 170 to exhaust to the outside of sound absorbing assembly 170. Rear casing 180 includes a plurality of second flanges 183 protruding radially outward at an opening end 180b of rear casing 180. Second flanges 183 correspond to first flanges 173 which are formed at opening end 172a of front casing 172. Second locking holes 185 are formed in second flanges 173, respectively. Rear cap 182 is engaged with rear end 176b of motor assembly 176 at the time that sound absorbing assembly 170 is assembled. Rear cap 182 is exposed to the outside of sound absorbing assembly 170 through first through hole 178b and second through hole 181. Rear cap 182 alleviates a vibration which is generated during the operation of motor assembly 176.
Hereinbelow, an assembling process of sound absorbing assembly 170 of the conventional vacuum cleaner 100 as described above will be briefly described.
First, front cap 174 is fitted onto front end 175a of motor assembly 176. Then, rear cap 182 is inserted into first through hole 178b of air guide 178, thereby air guide 178 is engaged with rear cap 182. Under this state, air guide 178 is mounted onto motor assembly 176 in order to enclose rear half portion 175b of motor assembly 176.
Next, in order to enclose front cap 174, motor assembly 176, and air guide 178, which are engaged together, front casing 172 is engaged with rear casing 180. For this purpose, first locking holes 175, which are formed in first flanges 173 of front casing 172, and second locking holes 183, which are formed in second flanges 183 of rear casing 180, are arranged in a row. Thereafter, a plurality of locking screws 185 are inserted into first locking holes 173 and second locking holes 183 in due sequence. Thereby, the assembling of sound absorbing assembly 170 is completed.
However, in the conventional sound absorbing assembly 170 as described above, in order to engage front casing 172 with rear casing 180, it is necessary to form first flanges 173 and second flanges 183 at an outer periphery of front casing 172 and at an outer periphery of rear casing 180. Further, it is necessary to employ locking screws 186, which are inserted into first locking holes 175 and second locking holes 185.
Accordingly, the manufacturing process and the assembling process of sound absorbing assembly 170 are complicated. Further, working time is largely wasted and the manufacturing cost of sound absorbing assembly 170 is high. In addition, an aperture can be produced at a screw connecting portion due to an incorrect screw connection or due to an elapse of time after the assembling of sound absorbing assembly 170. As a result, an exhaust air can leak through the aperture established between front casing 172 and rear casing 180. Thereby, the noise generated by motor assembly 176 during the operation of motor assembly 176 is increased.
U.S. Pat. No. 4,829,625 issued to Ta C. Wang on May 16, 1989 discloses a portable vacuum cleaner/air compressor having a vacuum casing and an impeller housing for enclosing a motor assembly. In Ta C. Wang's portable vacuum cleaner/air compressor, the motor assembly is disposed between the impeller housing, which encloses a plurality of impellers and the vacuum casing. The impeller housing is forcibly inserted into the vacuum cleaner.
However, in Ta C. Wang's portable vacuum cleaner/air compressor, a plurality of screws for engaging together an air intake cover enclosing the impeller housing, the impellers, the impeller housing and the motor assembly are employed. Accordingly, Ta C. Wang's portable vacuum cleaner/air compressor cannot completely solve the conventional problems as described above.